Electric snap switch



Jan. 23, 1940. R, BENTLEY 2,188,218

ELECTRIC SNAP SWITCH Filed May '7, 1937 5o 4/ 26 0M? 32A M INVENTOR .u .4. ROBERT H. BENTLEY BY HIS ATTORNEYS MMM wenn :ln-.23,1940 j 2,188,218

UNITED STATE-s Imi-Earl oFFlcE :.isazis e atnormc sNAr swrrcn Robert H. Bentley, Hartford, Conn., assigner to The Arrow-Hart & Hegeman Electric Company. e Hartford, Conn., a corporation of Connecticut Application May 7, 1937, Serial No. 141,372

4 Claims. (Cl. 20G-67) This invention relates to electric snap switches of a movable carriage designated generally by of the lever-operated type though the principles the numeral 2l. M of the invention may be applied to switches op- The carriage 20 may be formed of parallel meterated by push buttons or other types of operal side plates .22 and 24 which are maintained in ating means. spacedrelation by engagement with, or attach- 5 It is an object of my invention to provide an ment to, narrow parallel end plates 26 and 28. improved electric snap switch having a novel com- A convenient means of engagement between the bination of parts which may be inexpensively plates 22 and 24 and the end plates 26 and 28 manufactured and easily fabricated to provide a may be by the provision of pairs of spaced lugs, lo switch of positive operation and sturdy consuch as 22B and 22h, projecting from the side 1 struction. other objects and advantages of my edges of the plates 22 and 24 and fitting snugly invention will become apparent as it is described Within Openings DIOVided in the end plates 26 in connection with the accompanying drawing. and 23. The carriage 20 iS adapted t0 Slide With- In the drawing, Figure 1 is a side elevation in the space between the insulating blocks I0 and u u view of an electric snap switch embodying the l2 While being engaged with and guided by the principles of my invention; parallel surfaces Ill'L and I2*L of those insulating Figure 2 is e side elevation View ef the Switch blocks. To further guide the sliding motion o1' shown in Figure 1 but with one of the side inthe carriage 20 parallel gIOOVeS l and I6' may suleting plates removed te shew the interior be provided in the inner surfaces of the side inn 20 mechanism; sulating plates i4 and I6 for the reception of the Figure 3 is a View similar te Flgure 2 but with parallel side edges of the end plates 26 and 28. the parte of the switch in en intermediate posi- The bottom or the innermost edges of the side tien, prier te snapping from e to on posiplates 22 and 24 which are preferably made arcution; ate to minimize friction are engaged by the spring Figure 4 is a Sectign View taken transversely I1 Which thus tends fr0 bias the Carriage 2 Ilpu through the switch mechanism along line 4 4 Waldly of Figure 2; The top or outer surfaces of the side plates Figure 5 is a vertical Section View through the 22 and 24 are provided with identical V-notches, Switch Shown in Figure 1 with the Section being such as 22", in the apex of which is pivotally so .o taken along 5--5 of Figure 3. Supported a switching member, designated gen- Referring to the drawing the supporting means erally by the numeral 30. This switching memfor the switch mechanism comprises a pair of bel' is generally 0f UShape an@ embraces the identical insulating blocks I0 and I2 mounted in Side plates 22 and u 0f the Carnage and has its spaced relation between parallel insulating plates transverse POTOP 32 Passing through apel'tlus, .s

M and |5 and secured thereto by any suitable such as 22=, provided near the lower edge of the means. These plates may be recessed as at I4v to Pas aniitofsuch arees tOIPemt tle Oscill'ton allow movement of the switch parts. Also mount- 0 e SW c mg mem 1- n 0r er 0 Demi n' ed between the insulating plates I4 and I6 is a sermon of thelswtchmg member 1n the aperthird insulating block I3 positioned along the *tures 22 a passage 22p is cut to the outen o lower edge of the insulating plates I0 and I2 and edge of each 51de plate- The transverse Portion secured thereto in any suitable manner. The adof this switching {11?mbe1 is extended beyond the sides thereof providing extensions 32 and 32b for jacent portions of the lnsulatlng blocks I0, I2 and engagement of the iixed switch contacts 40 and 42 3 are cut back and, recessed to provide a T' hereinafter more fully described. The switching 45 Shapffd Chamber 5' m the bottom of which 1s member thus is a movable bridging contact, but 5 recelV-ed a bowed leaf SPrmg n Whose purpose obviously it could be employed as a contact mover y will he hereinafter described. If desired, several or cai-Iier mst-,en

of these insulating Darts may be integrally For the purpose of pivotally mounting the formed. As will be noted in the drawing the end switching member, oppositely directed inward ex- 5o 0f the leef spring l1 rests upon the upper 0r tensions or trunnions 34 are provided on the ends inner surface of the insulating block I3 forming of the para11e1 1egs of the switching memben the door of the chamber I5. In forming and These trunnions 34 engage with the apices of the positioning the insulating blocks III and i2 parnotches in the side plates 22 and 24. allel side faces Illa and I2l are provided in spaced For the purpose of influencing the movement Il relation to form guide surfaces for the side plates 0f the switching member, a at strut il is posiu tioned between the side plates o! the carriage 22 and 24 and is guided in its movement by sliding engagement with the faces oi" said plates. One end of this strut engages with the inner edge of the transverse portion 32 o! the switching member. 'I'he other end oi the strut is encaged bythe end of a manual operating member 52 which isV pivoted upon pin 54 passing through and mounted in the side insulating plates I4 and I6 of the switch. An insulating handle 56 is provided on the end of the manual operating member in the usual fashion. Oscillatory movement of the manual operating member is limited in any suitable fashion, such as by engagement of the member with the insulating blocks l and I2.

For the purpose of reducing friction, cooperating arcuate surfaces are provided for engagement between the strut 50 and the manual operating member. A similar arcuate surface is provided on the lower end of the strut which engages with the switching member.

From the foregoing description the operation of the switch may now be understood. Assuming the switch to be in the o position as illustrated in Figure 2, the handle 56 may be grasped and oscillated in a counter-clockwise direction into the position as shown in Figure 3. Incoming into this position the strut 50 has moved to the right and forced the carriage 2n downwardly against the stress of the spring I'l by reason of the force from the strut being transmitted to the carriage through the switching member. Movement any further in a counterclockwise direction by the handle will cause the parts to pass through a critical or dead-center position and the force of the spring l'l will then cause the switching member. to move with a snap action into the closed-circuit position as shown in Figure 1. In this position the carriage will again have risen to the position in which it is shown in Figure 2. Y

It will be observed that due to the reciprocating movement of the carriage 20 the switching member moves rectilinearly downwardly against the effort of the spring l1 until the dead center position of the parts is reached. At that time the switching member starts to move to its new position and in so doing moves along a curved path as it swings about its pivotal mounting ln the carriage while the carriage is simultaneously being pressed up to its original position by the spring I1. The path of movement of the movable contact surfaces is illustrated by dotted lines P in Figure 1. The reverse movement of the movable contact is accomplished when the switch is snapped from on (full lines, Fig. 1) to off (dotted lines, Fig. 1) position. Thus, the movable contact surfaces of the switching member have a wiping action when coming into engagement with the fixed contacts. A valuable feature of my invention is the wiping action tending to keep the contact surfaces al- Ways clean and bright.

In order to accommodate the unusual movement of the .movable switch contact the fixed contacts 40 and 42 are flared outwardly at their lower edges as may best be seen in Figure 5.

aieaais 'Ihese iixed contacts may be made of resilient sheet metal and secured to the outside surfaces of the side plates I4 and I6 in any suitable fashion. In the embodiment of the invention shown in the drawing there are terminal plates 4I and 43 connected with or attached to the ilxed contacts but obviously the contacts and terminal plates may be varied in construction.

Many modifications within the scope of my invention will occur to those skilled in the art. Therefore I do not limit myself to the specic form of the invention as illustrated in the drawing.

I claim:

1. In an electric switch, rectilinearly movable l supporting means, a movable contact pivotally mounted on said supporting means, a leaf spring engaging and biasing said supporting means in a position to maintain said contact in one or another of two positions, manually operable means for operating the switch, an incompressible member connecting said manual means and said contact, said supporting means moving in response to movement of said manual means and in opposition to said biasfor causing movement of said contact to a new position with a snap when said supporting means. reaches the limit of its bias-opposing movement.

2. In an electric switch, an insulating base, a carriage rectilinearly slidable therein, a movable contact pivotally mounted on said carriage, an operating lever, rigid means connecting said lever and movable contact, and leaf spring biasl ing means engaging a curved portionl of said carriage whereby said switching member is moved with a snap action after predetermined movement of said lever.

3. In an electric switch, an insulating base,

a rectlinearly slidable carriage comprising parallel plates joined at their side edges by bearing plates, a. yoke pivotally mounted on said carriage and having contact surfaces, a pivoted manual operating member, a non-compressible member pivotally connecting said operating member and said yoke and positioned between said parallel plates to be guided thereby, resilient means acting on said carriage and compressible to cause operation of said yoke with a snap, fixed contacts engageable and disengageable'by said contact surfaces with a combined rotary and rectilinear motion to keep the contact surfaces clean and prevent sticking.

4. In an electric switch, an insulating base, a rectilinearly slidable carriage comprising parallel plates joined at their side edges by bearing plates, a yoke having lateral bearing extensions adapted to be seated in V-notches provided in said parallel plates, a pivoted manual operating member, a non-compressible member pivotally connecting said operating member and said yoke and positioned between said parallel plates to be guided thereby, resilient means acting on said carriage and compressible to cause operation oi said yoke with ar snap, xed contacts engageable and disengageable by said lontact surfaces with a combined rotary and rectilinear motion to keep the contact surfaces clean and prevent sticking.

ROBERT H. BENTLEY. 

